.head{
    color: orangered;
    font-size: 40px;
    height: 100px;  
    line-height: 100px;  
    text-align: center; 
}    
.contonter {  
    margin-top: 100px;
    height: 100%;  
    display: flex;  
    justify-content: center; /* 水平居中 */  
    align-items: center; /* 垂直居中 */  
}  
